Both the Clinton and Trump campaigns have hit the ground hard in Arizona, Florida, Nevada and Pennsylvania, and new CNN/ORC polls across the four states paint a picture of a tight race to the finish in critical battlegrounds.

Clinton holds a 4-point edge among likely voters in the historically blue-tilting Pennsylvania, and Trump tops Clinton by 5 with voters in red-leaning Arizona. Though both states tilt in the same direction as their 2012 results, the leaders' margins are tighter than their predecessors' final leads were in each state.

Florida appears to be as tight a contest as ever, with Clinton at 49% among likely voters and Trump at 47%. That's an apparent shift in Clinton's direction since the last CNN/ORC poll there in September before the presidential debates began, but still a within-margin-of-error race.

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In Nevada, the poll suggests the race has also shifted, with Trump now ahead there 49% to 43%, with 5% behind Libertarian Gary Johnson, compared with a two-point Clinton edge in mid-October.

Tight Senate races, too
All four of these states also have senate seats up for grabs this year, three of the four are incredibly close contests. In Florida, Marco Rubio's once wide lead over Patrick Murphy has evaporated, and the race is now a 1-point contest, 49% back Rubio, 48% Murphy. The Nevada race to replace the Senate's top Democrat Harry Reid has swung back toward Republican Joe Heck, but here too the race is within margin of error, with Heck at 49% to Catherine Cortez Masto's 47%. The margin widens slightly in Pennsylvania, where Republican incumbent Pat Toomey lags behind challenger Katie McGinty by 5 points. In Arizona, John McCain holds a wide lead over challenger Ann Kirkpatrick, topping her 52% to 39%.